"Breeding-back" aims to restore or immitate extinct animals by selective breeding. This blog provides general information, the facts behind myths and news from various projects.

Friday, 17 January 2014

What makes breeding-back so fascinating?

I have
always been fascinated with extinct animals, among dinosaurs especially those
that have been exterminated by man. The thylacine was the hero of my early
childhood. When I rediscovered this subject for me some years ago, and
researched on all the exterminated megafauna around the globe, I inevitably concerned
myself with the aurochs and heard of those “breeding-back” attempts. The idea
fascinated me – selective breeding with living descendants in order to reconstruct
the original wild type and to fill a gap in nature man created. I became almost
obsessed with this idea, so that I always feel I have to explain myself why I engage
myself with the horn shapes of some cows or the coat colour of some horses. It is
true that the whole breeding-back issue is a very narrow niche, but to me it is
connected to a lot of other fields.

Arguing
about the need of reintroducing aurochs-like cattle and primitive horses into their
former range partly depends on the so-called megaherbivore hypothesis which
claims large herbivores through their interaction with the flora more diverse
landscapes than a closed canopy forest or climax biotope would be. I am no
hardliner of that thesis (some of them suggest that Europe would be an open
savannah/grassland with huge herds of herbivores like the African Serengeti) but
I think large herbivores do have an influence on the flora they live in, though
certainly not a larger one than climate, soil parameters and terrain. There is
a lot of literature on this subject to dig in, and it is exciting for me to try
to compose a synthesis of that highly polarized discussion. The megaherbivore
hypothesis itself is connected with the Overkill hypothesis that suggests that
many members of the megafauna that died out towards the end of the last glacial
period or shortly after it are victims of early human hunters. As the theory
outlined above, this is another very controversial and emotionalized subject –
I had been concerning myself with this issue years before I discovered
breeding-back for me, but I won’t discuss it here any further because it is not
really relevant for breeding-back.

I always
want to emphasize that breeding-back is not simply something for fanciers that
want to create the breed of their dreams and keep them on paddock is or in
zoos, but that it is the long-term goal to create an authentic, ecologic
substitute for the extinct archetypes they are bred to resemble. These animals
even now have a practical use in conservation and demonstrate their importance
in their former ecosystems; regardless of how large the impact of
megaherbivores on landscapes really is, they were and are important for a lot
of species in their native biotopes. Many grazing projects in Germany, the
Netherlands and other countries underline that.

Reintroduction of large
herbivores also provide empirical tests for hypotheses like the megaherbivore
hypothesis or the cascade caused by the lack of predators which leads to a high
population density of herbivores and therefore overgrazing, and what that means
for the interaction between herbivores and the biodiversity of flora and fauna.
Breeding-back is a tool of conservation because releasing their results into their
native habitats is the reintroduction of a native species. That is why large
reintroduction initiatives like Rewilding Europe have integrated primitive
cattle and horses into their programmes. Europe’s megafauna without wild cattle
and horses as much as Southern Africa without populations of the Plain’s zebra
simply would not be complete, and breeding-back gives us the chance to fill
that gap in the most satisfying way.

The
breeding process itself requires to have some knowledge on the rules of
inheritance and its relevance for breeding a certain desired phenotype.
Inevitably you get into colour genetics. I also try to find out more about the
difference of qualitative and quantitative features and how to select
efficiently on the latter traits. Furthermore, population genetics are relevant
for breeding-back. If you finally have a herd (or several herds) of animals
with the desired features and start to expand and fragment the population the
genetic composition of the new sub-populations gets changed, and some will have
a higher portion of undesired recessive alleles or variations of any trait than
others, leading to phenotypic more or less diverging herds (genetic drift). Genetics
also are the tool to determinate whether there was local introgression from aurochs
or wild horses into their respective domestic counterparts and how extensive
that introgression was. It also explains why selective breeding just with
related animals that do neither descend from the desired extinct animal nor
contain all the genes in the extinct gene pool will only produce a superficial similarity.
I’m an amateur on genetics but breeding-back certainly increased my knowledge a
lot.

Breeding-back
is closely connected with dedomestication. To me, dedomestication is exciting
because it actually is evolution happening in front of our eyes – yet feral
animals are sadly often considered ecological pests and invasive species by the
majority of biologists (in many ecosystems they certainly are, though) and are
under-studied. Of course the environment influences the condition of the body
of the animals, but the changes observed in domestic animals becoming feral are
certainly also genetic, and in many cases “new old traits” evolve, phenotypic
as much as behavioural. The pleiotrophic effects involved in dedomestication
surprisingly favours features not intuitively thought to be influenced by
natural/sexual selection after only a few generations in the wild; this is
exactly the reversal of what has been observed in the Farm fox experiment,
which aims to study the genetic, phenotypic and behavioural changes caused by
domestication.

Feral hogs in Alabama

In fact, breeding-back also requires to research on the changes
that wild animals go through while being domesticated to better understand how
a non-dedomesticated breeding-back result will be different from the desired
extinct wild type. Feral cattle and horses are prime models for filling gaps in
our knowledge about the social behaviour and ecology of their wild types, so
that there is a mutual gain of information: the desired archetype tells us what
breeding-back has to focus on, and results of breeding-back living semi-feral
or feral tell us some aspects about the extinct archetypes we otherwise could
never know from the limited data we have.

Furthermore,
breeding-back is also an exciting historical, archaeological and paleontological
puzzle, because doing that work efficiently requires a profound knowledge on
the extinct animals you are focusing on. What did it look like exactly? What do
we know about its behaviour and its ecologic niche? What was its preferred
habitat and its influence on other faunal and floral species? How large was its
total range in a climatically comparable period? What were the causes of its
extinction and the chronology of this process? In order to answer these
questions information obtained from the sources mentioned above have to be put
together properly, and you have to know where to look for and which sources are
trustable and which are not. Many historic references are reproduced only from
second or third hand, leading to confusions and Chinese whispers. The more
information you have, the more complete the picture will get. You constantly
have to reconsider the conclusions you have drawn previously, often leading to
surprises, and pay attention that your view does not turn into a static thought
system and biased view – this would be exactly the opposite of scientific
thinking, and unfortunately sometimes is practised by exactly those who claim
to have the only scientific approach.

Researching on other wild bovines brings you information about the aurochs and vice versa

The species
that are the goal of breeding-back projects also can serve as models for their
taxonomic group. The Aurochs, Quagga and Tarpan engage me to concern myself
with bovine and equine evolution and phylogeny, and researching on related
species is always very helpful as it might have some implication for reconstructing
the biology of their extinct relatives. The basic anatomy, digestion systems
etc. are roughly the same among perissodactyls and ruminants, so if you learn
about the physiology of cattle and horses you learn about the physiology of a
whole set of species. Furthermore, it is interesting to compare the social
behaviour of the different species. For example, that of each of the wild
bovines (buffaloes excluded) is about the same. What is the purpose of the
exceptional sexual dichromatism displayed by some bovids, which is rather
unusual among mammals? Why do horses and bison not show it? Therefore,
researching on the biology of these very few species gives a clue on the
biology of a lot of mammals in general.

For me as a
self-thought amateur animal artist, the obsession of drawing the one accurate
and satisfying reconstruction of whatever species relevant for breeding-back is
very helpful for improving my artistic skills. As I drew extinct dinosaurs and
other Mesozoic reptiles for many years, I was quite inexperienced when I
started drawing exterminated mammals.Not
only did drawing loads of aurochs increase my knowledge on mammalian
soft-tissue anatomy a lot, it also is incredibly refreshing to shift from
dinosaurs to herbivorous mammals. But art is not only relevant for me.
Qualitative, artistic reconstructions are important for breeding back because
it shows what the breeding has to focus on, and how the animals have to look
like to be satisfying. If you don’t know the appearance of the desired end result,
you cannot select for it.

As you see, breeding-back motivates you to dig into a diverse set of subjects and always remains interesting and versatile.

4 comments:

I think they pretty much reached the limit of what selective breeding can do, to achieve a greater resemblance real dedomestication would be necessary: release a number of Tamaskan into a reserve with deer and other prey animals and do not interfere. I think they would evolve more wolf-like skulls, larger brain size, more complex social behaviour and whatever else traits that would be re-developed by pleiotropic effects and natural selection. But even then they probably would still not be identical with grey wolves, although very similar. That's the way I see it at least.

About this blog

This blog is on everything related to the so-called “breeding-back” of extinct animals: From the extinct animals themselves, over their often domestic descendants and dedomestication to news and facts about various breeding-back projects, reports and photos from my own breeding-back related trips. I try to have a balanced and fact-based approach to this subject and to dismantle many of the popular myths. Enjoy!

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About me

I am an Austrian student of biology/zoology at the University of Vienna. My major interest always have been extinct animals, from dinosaurs to Pleistocene megafauna and more recent extinctions. Besides that I am interested in evolution, genetics and ecology.
I am also an amateur animal artist, making drawings and models mostly of extinct animals.